Roadway grinding/cutting apparatus and monitoring system

ABSTRACT

An apparatus and method is provided for monitoring operation of a roadway grinding/cutting machine of the type configured to travel along a roadway while engaging and grinding the roadway with a grinding/cutting head. A first displacement sensor generates, during the travel, first distance data associated with a distance between a reference level and a location on the roadway ahead of the grinding zone. A second displacement sensor generates, during the travel, second distance data associated with a distance between the reference level and a location on the roadway behind the grinding zone. A processor captures and uses the first and second distance data to determine a depth of cut as grinding/cutting progresses.

BACKGROUND

1. Technical Field

This invention relates to vehicles equipped with abrasive saw blades forcutting concrete, stone, asphalt and other similar surfaces, and inparticular, to a monitoring system mounted on these vehicles forproviding in-process feedback to control operation of the saw blades,and to enable analyses of blade performance and the grinding operation.

2. Background Information

The present invention is described below in connection with the concreteindustry by way of example only but is equally useful in cutting otherhard surfaces. Moreover, the use of diamond abrasive is described by wayof example only, with the understanding that as used herein, the term“diamond” or “diamond abrasive” collectively refers to nominally anytype of superabrasive, including CBN (cubic boron nitride), PCD(polycrystalline diamond), and single crystal synthetic diamond ornatural diamond, with or without metal cladding used to improve grainretention in the finished product.

The resurfacing of highways, bridges and airport runways is asignificant application for superabrasive products. The practice ofrestoring roadways with superabrasive grinding wheels is commonlyreferred to as “diamond grinding”. Diamond grinding improves bothtraction and ride smoothness. This technology has been successfully usedin the US since about 1965 to extend the life of roadways at a fractionof the cost of conventional concrete overlay techniques.

This roadway grinding is commonly accomplished with custom builtmachines that support a concentric assembly of blades (thin grindingwheels), each including a metal (e.g., steel) core with metal-bondedsuperabrasive segments distributed circumferentially thereon. The bladesare typically about 14 in (35 cm) in diameter and 0.2 in (0.5 cm) or 0.6in (1.5 cm) wide. On a single arbor (axis), 170-280 blades may bemounted. This assembly is driven by a large diesel engine (300-750 hp)to achieve a typical depth of cut of ⅛ in (0.3 cm) to 1 in (2.5 cm) at agrinding rate of about 15 ft/min (4.6 m/min) over the highway. Thesegrinding systems can run continuously, or with few breaks, for manyhours.

The machine typically provides little information to the machineoperator regarding the state of the grinding process. Engine rpm andhydraulic pressure applied to the grinding wheels may be displayed tothe operator on some machines. The operator primarily relies on suchinformation and visual or audible clues to assess the performance of themachine and the grinding wheel assembly.

The lack of quantitative process measurement and analysis may lead toproblems in these superabrasive grinding operations. Small systemvariations that are unknown to the operator, such as a variation indepth of cut across the length of the grinding wheel assembly axis, orinsufficient cooling water supply, can lead to undesirable grindingconditions and premature failure of various components. Other machinerelated problems, such as failure of the grinding head bearings, mayalso result in a costly shut-down of grinding operations.

Thus, a need exists for a monitoring system capable of providing anoperator of the aforementioned grinding machines with in-process(real-time) information on the state of the on-going grinding operation,for use in maintaining the performance of the grinding system.

SUMMARY

An aspect of the invention includes an apparatus for monitoringoperation of a roadway grinding machine of the type configured to travelalong a roadway while engaging and grinding the roadway with a grindinghead. A first displacement sensor generates, during the travel, firstdistance data associated with a distance between a reference level and alocation on the roadway ahead of the grinding zone. A seconddisplacement sensor generates, during the travel, second distance dataassociated with a distance between the reference level and a location onthe roadway behind the grinding zone. A processor captures and uses thefirst and second distance data to determine a depth of cut duringgrinding operations.

Another aspect of the invention includes an apparatus for grindingconcrete roadways. The apparatus includes a ground engaging vehicleconfigured to travel along the roadway while supporting and driving agrinding head having a plurality of circular blades spaced co-axiallyalong a central axis, each blade having a plurality of superabrasivescircumferentially spaced thereon. The grinding head is displaceable toengage and grind the roadway at a grinding zone during the travel.Coolant means supplies coolant to the grinding zone and collects thecoolant after use. The apparatus also includes a grinding monitoringsystem including a first displacement sensor to generate, during thetravel, first distance data associated with a distance between areference level and a location on the roadway ahead of the grindingzone. A second displacement sensor generates, during the travel, seconddistance data associated with a distance between the reference level anda location on the roadway behind the grinding zone. A third displacementsensor generates third distance data associated with a distance betweena circumference of the blades and a predetermined position relative tothe axis. A pressure sensor generates, during the travel, pressure dataassociated with pressure of the coolant. A temperature detectorgenerates, during the travel, temperature data associated with thecoolant at a supply location and at a collection location. A vehiclespeed sensor generates, during the travel, data associated with speed oftravel along the roadway. A vibration sensor generates, during thetravel, vibration data associated with the vehicle. A processor capturesand uses the data to determine depth of cut and blade wear duringgrinding. An output device is coupled to the processor, and theprocessor captures the data and displays on the output device, duringgrinding operations, at least one of the parameters selected from thegroup consisting of distance traveled, area of roadway ground, volume ofmaterial removed, abrasive cost per unit area of surface ground, vehiclespeed, grinding head rpm, vibration, depth of cut, coolant pressure,coolant inlet temperature, coolant outlet temperature, blade wear, andcombinations thereof.

In another aspect of the invention, an apparatus for grinding concreteroadways includes a ground engaging means for traveling along a roadwayin a direction of movement, the ground engaging means supporting agrinding means thereon. The grinding means has a central axis and aplurality of circular blades spaced co-axially thereon, each bladehaving a plurality of circumferentially spaced abrasives. An enginemeans is configured to drive the grinding means. The grinding means isdisplaceable to engage and grind the roadway at a grinding zone duringthe travel. A grinding monitoring system includes first displacementsensing means for capturing, during the travel, first distance dataassociated with a distance between a reference level and a location onthe roadway ahead of the grinding zone in the direction of movement. Thegrinding monitoring system also includes second displacement sensingmeans for capturing, during the travel, second distance data associatedwith a distance between the reference level and a location on theroadway behind the grinding zone in the direction of movement.Processing means is provided for capturing and using the first andsecond distance data to determine depth of cut during grindingoperations.

In a further aspect of the invention, a method for grinding concreteroadways includes operating a ground engaging vehicle to travel along aroadway in a direction of movement, and to rotationally drive a grindinghead having a plurality of circular blades spaced co-axially on acentral axis, each blade having a plurality of abrasivescircumferentially spaced thereon. The grinding head is displaced toengage and grind the roadway at a grinding zone during the travel. Themethod also includes operating a grinding monitoring system including afirst displacement sensor to generate, during the travel, first distancedata associated with a distance between a reference level and a locationon the roadway ahead of the grinding zone in the direction of movement.A second displacement sensor generates, during the travel, seconddistance data associated with a distance between the reference level anda location on the roadway behind the grinding zone in the direction ofmovement. A processor captures and uses the first and second distancedata to determine depth of cut during grinding operations. The methodalso includes generating, during the foregoing operations, at least oneof the parameters selected from the group consisting of distancetraveled, area of roadway ground, volume of material removed, abrasivecost per unit area of surface ground, vehicle speed, grinding head rpm,vibration, depth of cut, coolant pressure, coolant inlet temperature,coolant outlet temperature, blade wear, and combinations thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of this invention will bemore readily apparent from a reading of the following detaileddescription of various aspects of the invention taken in conjunctionwith the accompanying drawings, in which:

FIG. 1A is a schematic elevational view of a roadway grinding machine onwhich an embodiment of the present invention is installed;

FIG. 1B is a perspective view, on an enlarged scale, with portionsbroken away, of a portion of the roadway grinding machine andinstallation of FIG. 1A; and

FIGS. 2 and 3 are graphical displays of outputs generated by theembodiment of FIGS. 1A and 1B.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings that form a part hereof, and in which is shown byway of illustration, specific embodiments in which the invention may bepracticed. These embodiments are described in sufficient detail toenable one to practice the invention, and other embodiments will beapparent in light of this disclosure. It is also to be understood thatstructural, procedural and system changes may be made without departingfrom the spirit and scope of the present invention. The followingdetailed description is, therefore, not to be taken in a limiting sense,and the scope of the present invention is defined by the appended claimsand their equivalents. For clarity of exposition, like features shown inthe accompanying drawings are indicated with like reference numerals andsimilar features as shown in alternate embodiments in the drawings areindicated with similar reference numerals.

Briefly, embodiments of the present invention include a monitoringsystem capable of capturing information on the state of roadway grindingoperations and using the information to generate output (e.g., duringgrinding or “in-process”) that may be used by the operator of theroadway grinding machine to maintain or optimize grinding performance.These embodiments may not only assist the operator in controlling thegrinding process, but may also benefit the abrasive product supplier andthe contractor. The abrasive product manufacturer, for instance, may useinformation on usage and performance of the grinding wheels to properlyprice the abrasive product, and to improve the design (performance) ofthese products for particular grinding operations. Similarly, thecontractor may use information on machine usage to facilitate jobquoting to prospective customers.

Particular embodiments include a system that automatically measures,records, analyzes and reports key operational and performance parametersin roadway grinding applications. For ease of discussion, embodiments ofthe present invention are shown and described with respect toconventional roadway grinding operations, using a roadway grindingmachine 12 supporting a plurality of blades 18. It should be understood,however, that embodiments of the invention may be used in connectionwith substantially any grinding and/or cutting operation effected upon aroadway, tarmac, or other vehicle supporting surface, by one or morevehicularly supported grinding and/or cutting blades.

Where used in this disclosure, the term “axial” when used in connectionwith an element described herein, refers to a direction substantiallyparallel to axis 17 of a blade 18 when installed on grinding machine 12as shown in FIGS. 1A and 1B. The term “in-process” and/or “real-time”refers to the capture and processing of events as a roadway grindingprocess proceeds, e.g., to provide feedback during on-going operations.

Referring now to FIGS. 1A-4, embodiments of the present invention willbe more thoroughly described. As shown in FIGS. 1A and 1B, a system 10of the present invention may be used in conjunction with a roadwaygrinding machine 12 in the form of a ground engaging vehicle configuredto travel along a roadway 13 in a direction of movement 14. Exemplaryvehicles include a main frame 11 and a grinding wheel frame 16configured to support a grinding head 15 along a grinding head axis ofrotation 17. Grinding head 15 includes a plurality of circular blades 18(FIG. 1A) spaced co-axially thereon. The blades 18 may be constructed inany manner suited to the particular grinding operation. In typicalembodiments, blades 18 are relatively thin grinding wheels, eachincluding a steel core with a plurality of metal-bonded abrasive (e.g.,superabrasive including natural or synthetic diamond, PCD or CBN)segments 20 spaced circumferentially thereon. The blades are typicallyabout 14 in (35 cm) in diameter and 0.2 in (0.5 cm) or 0.6 in (1.5 cm)wide, though substantially any size blades may be used. In typicalembodiments, 170 to 280 blades may be mounted along a single axis 17,though greater or fewer blades may be used depending on needs dictatedby particular grinding, applications. An engine 22 (typically 300 to 750hp) drives grinding head 16 about axis 17.

The grinding head 16 is displaceable, e.g., vertically, relative tovehicle 12, to engage and grind roadway 13 at a grinding zone 24, as thevehicle travels along the roadway in direction 14. In the exemplaryembodiment shown, this displacement may be effected and controlled byadjusting conventional depth wheel assemblies 25 in combination withpressure applied by hydraulic cylinders 26. Wheel assemblies 25 andcylinders 26 may be actuated to raise and lower grinding head 15 byrotating grinding wheel frame 16 about pivot 28, to achieve a desireddepth of cut. In typical applications, a depth of cut (Δd) of ⅛ in (0.3cm) to 1 in (2.5 cm) may be achieved at rate of about 15 ft/min (4.6m/min) over the roadway (i.e., in direction 14).

Other components of vehicle 12 include steering wheels 29, and traction(drive) wheels 30 driven in a conventional manner by a drive engine 32.As shown, traction wheels 30 are pivotably supported by a traction frame34 which may be pivoted by hydraulic cylinder 36 to apply downward forceas desired to increase traction of the wheels 30. In variousembodiments, a coolant (e.g., water) tank 40 may be coupled to nozzleand collector assemblies 42, 44, which respectively apply coolant to,and collect used coolant from, grinding zone 24 in a conventionalmanner. An example of a roadway grinding machine of the type describedherein, and to which embodiments of the present invention may be readilyapplied, is known as the Boart-Longyear PC5000B.

Turning now to FIG. 1B in particular, monitoring system 10 includes oneor more first displacement sensors 50 (e.g., ultrasonic sensorssupported by vehicle 12) configured to detect the distance d1 between apredetermined reference level (e.g., on main frame 11) and a location onroadway 13 ahead of grinding zone 24 in the direction of movement.Similarly, one or more second displacement sensors 52 are disposed todetect the distance d2 between a predetermined reference level and alocation on roadway 13 behind grinding zone 24 in the direction ofmovement. Sensors 50 and 52 are communicably coupled to a processor 54,such as provided by a personal computer or hand-held device such as aPDA (Personal Digital Assistant) or Smart phone. Such communication maybe provided in any suitable manner, e.g., by wire or wirelessly.Processor 54 is configured to capture and use the distance data d1, d2,to determine the depth of cut Δd during grinding operations.

In particular embodiments, this depth of cut information is provided byfour ultrasonic displacement sensors (e.g., a pair of sensors 50, 52 atopposite ends of axis 17 to provide depth of cut information at bothends of grinding head 16). An algorithm may use this information,together with data on the positions of the sensors with respect to eachother and the machine, to calculate the depth of cut Δd.

The depth of cut Δd is determined in-process, i.e., while grinding isbeing performed, to provide in-process feedback to the machine operator,and/or automatically to the machine itself (such as by use of suitableelectronic controls). This feedback may thus be used to adjust theheight of grinding head 15 as the grinding operation progresses.

In light of the instant disclosure, the reader will recognize that inorder to provide desired levels of measurement accuracy, the depth ofcut apparatus may be calibrated from time to time. This may beaccomplished, for example, by placing the grinding head 18 into a knowndepth of cut position, e.g., by lowering the grinding head 18 to contacta ground (or pre-ground) portion of the roadway 13. With the machine 10stationary, a calibration routine may then be executed, e.g., byprocessor 54, in which the user is prompted to enter the known depth ofcut position (e.g., zero, if head 18 is resting on an uncut portion ofroadway). This routine may then correlate the known depth to the variousmeasurements captured by the system 10, such as the output of sensors50, 52, the angular position of the frame 16 (as may be determined bydepth wheel assemblies 25 and hydraulic cylinders 26), and theinformation provided by sensors 53 with respect to the axis of thegrinding wheel 18.

System 10 may optionally include one or more third displacement sensors53 (e.g., ultrasonic sensors) configured to detect, during grindingoperations, the distance d3 between an outermost circumference of atleast one of the blades 18 and a predetermined position relative to axis17. For example, as shown, sensors 53 may be disposed on wheel guardportions 56, 58, which are supported by frame 16 at a predetermineddistance(s) from axis 17. Sensor(s) 53 are communicably coupled toprocessor 54, which captures the distance d3 and calculates blade wearassociated with the grinding operations.

In particular embodiments, ultrasonic sensors 53 are placed at opposite(axial) ends of grinding head 15, e.g., on guard 56, and may beprotected from debris by additional manually operated guards (notshown). For example, in the event such additional guards are used,sensors 53 may be actuated once grinding operations have been halted andthe guards are opened. Alternatively, such as when grinding relativelysoft materials less likely to damage the sensors, the additional guardsmay not be used, or may simply be left open to enable use of sensors 53during grinding. Each of the sensors 53 may generate d3 distance datawhich is then captured and converted by processor 54 into head diameterfor both ends (i.e., the left and right sides) of grinding head 15.

Referring back to FIG. 1A, as further options, pressure sensors 60and/or temperature sensors 62 may be coupled to the coolant supply andcollection means, to detect the pressure and/or temperature of coolantflowing to and from nozzles and collectors 42, 44. A vehicle speedsensor 64, engine speed sensor 66, and/or vibration sensor 68 may alsobe disposed to detect vehicle speed, engine speed, and vibration data(e.g., of grinding head 15) during grinding operations.

While the data captured in-process may, in various embodiments, beoutputted to a user or operator in-process, such data may also bestored, e.g., in non-volatile memory 70 or other data historian databaseassociated with processor 54, and outputted after grinding operationshave been completed, such as discussed in greater detail hereinbelow. Inthis manner, data from various grinding operations may be aggregated,such as to facilitate compilation of detailed historical reporting andanalysis.

In particular embodiments, vehicle speed sensors 64, for example, mayinclude proximity sensors disposed to sense the presence of targetsspaced circumferentially along the hub of a vehicle wheel 29. Therotational rate of wheel 29 may then be calculated by measuring andanalyzing the time between voltage pulses generated as each target movespast the sensor. By considering the radius of the wheel, this rotationalrate may be converted to the speed of the machine 12 along roadway 13.Moreover, the direction of motion may be determined in any convenientmanner, such as through the use of dedicated sensors (not shown)configured to determine the orientation of steering wheels 29 relativeto frame 16. Alternatively, such as in the event multiple steeringwheels 29 are laterally spaced from one another, the direction of motionmay be determined by analyzing the sequence of pulses from sensorsassociated with steering wheels 29 disposed on opposite (e.g., left andright hand) sides of machine 12.

Vibration sensor 68 may include an accelerometer mounted at any suitablelocation on the grinding wheel frame 16 as shown. The absolute orrelative amount of acceleration or displacement due to vibration may becaptured by processor 54 and recorded by historian 70. Processor 54 maythen perform a Fourier or other analysis of the vibration signal data,such as to isolate dominant vibration frequencies and/or to otherwiserelate the vibration data to factors such as severity of the grind, headimbalance, bearing problems, etc.

Engine speed sensor 66 may include any suitable device or system capableof generating an output corresponding to engine rpm. In someembodiments, a proximity detector may be disposed in proximity to engine22 or to grinding head 15 to generate a pulse when a circumferentiallymounted target rotates past it. Alternatively, the Electronic ControlUnit (ECU) commonly associated with engine 22 may be communicablycoupled to processor 54 to supply engine rpm and/or other data such asengine power, etc.

The data generated from any of the aforementioned sensors may becaptured by processor 54 in the manner described hereinabove withrespect to sensors 50, 52, 53, and stamped by the processor with thetime and date of acquisition. This data may then be outputted byprocessor 54 in-process, (e.g., to an optional user interface 72, suchas an LCD touch screen) for use by the machine operator (orautomatically by the machine itself) as grinding progresses.

While the various sensors, processor 54, historian 70 and optional userinterface 72 may be disposed on vehicle 12, any one or more of thesecomponents may be disposed remotely from the vehicle. For example,various components of system 10, e.g., sensors, processor, userinterface/display, etc., may be wirelessly coupled to one another, e.g.,using Wi-Fi (802.11x), cellular (e.g., GPRS or GSM), and/or Bluetooth®(Bluetooth Sig, Inc., Bellevue Wash.) wireless connectivity. Suchwireless connectivity may be used to place various components, includingone or more of processor 54, database 70, and user interface 72 eitheron vehicle 12 (e.g., within operator station 74) or remotely, such as ata jobsite office or within a portable device (e.g., PDA or Smart Phone,etc.).

Referring to FIGS. 2 and 3, processor 54 and user interface 72 may beconfigured to display any of various parameters obtained or derived fromthe various captured sensor data. Distance traveled, area of roadwayground, volume of material removed, abrasive cost per unit area ofsurface ground, vehicle speed, grinding head rpm, grinding headvibration, depth of cut, coolant pressure, coolant inlet temperature,coolant outlet temperature, blade wear, and combinations thereof, mayall be displayed, e.g., as a function of time, by interface/screen 72.

For example, as shown in FIG. 2, vehicle speed is plotted as a functionof time at 74, while depth of cut on opposite (axial) ends of grindinghead 15 is shown as a function of the same time scale at 76, 78. By sucha display, a user can readily ascertain that in this instance, withother variables remaining constant, the depth of cut varies inverselywith the speed of vehicle travel along the roadway.

As shown in FIG. 3, vehicle speed is plotted as a function of time at80, while coolant pressure is also plotted at 82 as a function of thesame time scale. This display shows an increase in coolant pressureattributable to a clog in the coolant line at 84, followed by clearingat 86, a subsequent clog and clearing respectively at 88 and 90,followed by a catastrophic line clog at 92.

Examples of additional plots include the amount of abrasive remaining ongrinding head 15, based on the head specification and measurement ofwheel diameter. The abrasive cost per square yard of surface ground,which is a conventional measure of project costs, may then becalculated. Other parameters, such as the surface area and volume ofmaterial removed over a given time period, may also be calculated.

A representative embodiment of the invention having been described, thefollowing is a description of the operation thereof.

Monitoring system 10 may automatically start up and stand by for processmeasurement upon starting engine 22. Processor 54 then turns on andloads a suitable data acquisition program (e.g., LabView®, NationalInstruments Corporation, Austin, Tex.) and the array of various sensorsis powered. The machine operator may then input setup information, suchas project data and location on the roadway, which is then stored indatabase 70. The processor 54 continuously monitors the signals from thedepth of cut sensors 50, 52. When sensors 50, 52 indicated that grindinghead 15 has been lowered below a user-defined position, the dataacquisition program automatically transitions from data entry mode,which permits the user to input information, to data collection mode,where sensor measurements are captured and calculations are made andstored in database 70. The frequencies of data sampling and recording tothe database 70 may be defined by the user. During data collection(e.g., “in-process”), various parameters such as the depth of cut Δd,vehicle speed over ground, water pressure, relative vibration level,and/or various engine parameters such as engine speed and percent engineload, etc., may be displayed. Data entry and output may be provided witha user interface 72 such as a touch screen LCD mounted at operatorstation 74 or on a user's PDA or Smart phone. The acquisition of dataand the recording of information to database 70 continues until grindinghead 15 is raised above the user-defined threshold.

Optionally, information related to operational efficiency of vehicle 12may also be gathered. For example, upon system startup, the machineoperator may be prompted to enter a reason corresponding to the previousshutdown of the machine. Idle time may also be recorded in the database.

When engine 22 is turned off, power may be maintained to processor 54,which recognizes the turning off of an ignition switch (e.g., due to asignal sent via a relay) as initiation of machine shutdown. A connectionto a wireless network may then be made, such as via a wireless modemcard associated with processor 54, by which a data file stored indatabase 70 may be wirelessly transmitted, e.g., to a list of e-mailrecipients for remote storage. The processor 54 (e.g., computer) maythen automatically shut down once the data has been sent.

The data may be analyzed by processor 54 prior to shut down, and/orremotely by a recipient of the aforementioned data transmission. Ananalysis program, e.g., written in the Microsoft® Excel® (MicrosoftCorporation, Redmond, Wash.) spreadsheet application, may read thedatabase file(s) generated by system 12 and generate various plots, asdescribed hereinabove, that provide the user with insight into thegrinding operations either as they occur, or after operations have beenconcluded.

The following illustrative example is intended to demonstrate certainaspects of the present invention. It is to be understood that thisexample should not be construed as limiting.

EXAMPLE

A system 10 was fabricated substantially as shown and describedhereinabove. The roadway grinding machine was a Boart-Longyear PC5000B.Processor 54, memory 70 and user interface 72 were provided by a Wintelpersonal computer (i.e., a notebook computer having an Intel® (IntelCorporation) processor running a Windows™ (Microsoft Corporation)operating system). The following sensors were used.

Depth of Cut sensors 50, 52:

-   -   Migatron RPS-401 ultrasonic displacement transducers (4)

Grinding Head Diameter sensors 53:

-   -   Migatron RPS-401 ultrasonic displacement transducers (2)

Steering Wheel Motion (speed sensors 64):

-   -   Efector IGC206 inductive proximity sensor (2)

Engine RPM sensor 66 (grinding wheel head rpm sensor):

-   -   Efector IGC206 inductive proximity sensor

Machine Vibration sensor 68:

-   -   Kistler 5127B13 coupler and 8774A50 accelerometer

Cooling Water Pressure sensor 60:

-   -   Omega PX303-050G10V

Cooling Water Temperature sensor 62:

-   -   Omega fine-wire thermocouple (inlet & outlet temperature        measurement)

The above-described embodiments provide a monitoring system capable ofcapturing information on the state of roadway grinding operations andusing the information to generate output “in-process” that may be usedto maintain or optimize grinding performance. These embodiments may notonly assist in controlling the grinding process, but may also benefitthe abrasive product supplier and the contractor. The abrasive productmanufacturer may use information on usage and performance of thegrinding wheels to properly price the abrasive product, and/or toimprove the design (performance) of these products for particulargrinding operations. The contractor may use information on machine usageto facilitate job quoting.

Although embodiments of the invention have been shown and described inconnection with roadway grinding operations, it will be apparent inlight of this disclosure that the monitoring system hereof may be usedwith nominally any grinding or cutting operations, using one or moreblades, without departing from the spirit and scope of the presentinvention.

In the preceding specification, the invention has been described withreference to specific exemplary embodiments thereof. It will be evidentthat various modifications and changes may be made thereunto withoutdeparting from the broader spirit and scope of the invention as setforth in the claims that follow. The specification and drawings areaccordingly to be regarded in an illustrative rather than restrictivesense.

1. An apparatus for monitoring operation of a roadway grinding/cuttingmachine configured to travel along a roadway in a direction of movement,and having a grinding/cutting head displaceable relative to the machineto engage and grind the roadway at a grinding/cutting zone during thetravel, the apparatus comprising: one or more first displacement sensorsconfigured to generate, during said travel, first distance dataassociated with a distance between a predetermined reference level and alocation on the roadway ahead of the grinding zone in the direction ofmovement; one or more second displacement sensors configured togenerate, during said travel, second distance data associated with adistance between the predetermined reference level and a location on theroadway behind the grinding/cutting zone in the direction of movement;and a processor configured to capture and use said first and seconddistance data to determine a depth of cut during grinding/cuttingoperations.
 2. The apparatus of claim 1, comprising the machineincluding a ground engaging vehicle configured to travel along theroadway in the direction of movement, the head having a central axis anda plurality of circular blades spaced co-axially thereon, each bladehaving a plurality of abrasives circumferentially spaced thereon, and anengine configured to rotationally drive said head about said axis. 3.The apparatus of claim 1, comprising one or more third displacementsensors configured to generate third distance data associated with adistance between a circumference of said head and a predeterminedposition relative to an axis of rotation of said head.
 4. The apparatusof claim 3, wherein said predetermined position is on said machine. 5.The apparatus of claim 3, wherein said processor is configured tocapture and use said third distance data to determine head wear.
 6. Theapparatus of claim 5, wherein the head wear is determined duringgrinding/cutting operations.
 7. The apparatus of claim 1, wherein saidsensors are disposed on said machine and said predetermined referencelevel corresponds to a position on said machine.
 8. The apparatus ofclaim 1, wherein said processor is disposed remotely from said machine.9. The apparatus of claim 1, wherein said head is verticallydisplaceable relative to said machine.
 10. The apparatus of claim 1,comprising coolant means for supplying coolant to said head at thegrinding/cutting zone and for collecting said coolant after use.
 11. Theapparatus of claim 10, comprising a pressure sensor configured togenerate, during said travel, pressure data associated with pressure ofsaid coolant.
 12. The apparatus of claim 11, comprising a temperaturedetector configured to generate, during said travel, temperature dataassociated with pressure of said coolant at a supply location and at acollection location.
 13. The apparatus of claim 12, wherein saidprocessor is configured to capture and output said pressure andtemperature data.
 14. The apparatus of claim 1, comprising a speedsensor configured to generate, during said travel, speed data associatedwith speed of travel along the roadway.
 15. The apparatus of claim 14,wherein said processor is configured to capture and output said speeddata.
 16. The apparatus of claim 2, comprising an engine speed detectorconfigured to generate, during said travel, engine speed data.
 17. Theapparatus of claim 16, wherein said processor is configured to captureand output said engine speed data.
 18. The apparatus of claim 1,comprising a vibration sensor configured to generate, during saidtravel, vibration data associated with said machine.
 19. The apparatusof claim 18, wherein said processor is configured to capture and outputsaid vibration data.
 20. The apparatus of claim 1, wherein said data iscommunicated wirelessly.
 21. The apparatus of claim 1, comprising a userinterface configured to receive user input and display data outputted bysaid processor.
 22. The apparatus of claim 21, wherein said userinterface is configured to display at least one of the parametersselected from the group consisting of: distance traveled; area ofroadway ground; volume of material removed; abrasive cost per unit areaof surface ground; speed of travel; head rpm; vibration; depth of cut;coolant pressure; coolant supply temperature; coolant collectiontemperature; head wear; and combinations thereof.
 23. The apparatus ofclaim 1, wherein the abrasive is a superabrasive selected from the groupconsisting of: cubic boron nitride; polycrystalline diamond; singlecrystal synthetic diamond; single crystal natural diamond; andcombinations thereof with or without metal cladding.
 24. An apparatusfor grinding concrete roadways, the apparatus comprising: a groundengaging vehicle configured to travel along the roadway in a directionof movement; the vehicle supporting a grinding head thereon; saidgrinding head having a central axis and a plurality of circular bladesspaced co-axially thereon, each blade having a plurality ofsuperabrasives circumferentially spaced thereon; an engine configured torotationally drive said grinding head about said axis; said grindinghead being displaceable relative to said vehicle, wherein said grindinghead is configured to engage and grind the roadway at a grinding zoneduring said travel; coolant means for supplying coolant to said grindinghead at the grinding zone and for collecting said coolant after use; anda grinding monitoring system including: one or more first displacementsensors configured to generate, during said travel, first distance dataassociated with a distance between a predetermined reference level and alocation on the roadway ahead of the grinding zone in the direction ofmovement; one or more second displacement sensors configured togenerate, during said travel, second distance data associated with adistance between the predetermined reference level and a location on theroadway behind the grinding zone in the direction of movement; one ormore third displacement sensors configured to generate third distancedata associated with a distance between a circumference of said bladesand a predetermined position relative to said axis; a pressure sensorconfigured to generate, during said travel, pressure data associatedwith pressure of said coolant; a temperature detector configured togenerate, during said travel, temperature data associated with saidcoolant at a supply location and at a collection location; a vehiclespeed sensor configured to generate, during said travel, speed dataassociated with speed of travel along the roadway; a vibration sensorconfigured to generate, during said travel, vibration data associatedwith said vehicle; a processor configured to capture and use said datato determine depth of cut and blade wear during grinding; an outputdevice coupled to said processor; said processor configured to capturesaid data and display on said output device, during grinding operations,at least one of the parameters selected from the group consisting ofdistance traveled, area of roadway ground, volume of material removed,abrasive cost per unit area of surface ground, vehicle speed, grindinghead rpm, vibration, depth of cut, coolant pressure, coolant inlettemperature, coolant outlet temperature, blade wear, and combinationsthereof.
 25. An apparatus for grinding/cutting concrete roadways, theapparatus comprising: a ground engaging means for traveling along aroadway in a direction of movement; the ground engaging means supportinga grinding/cutting means thereon; said grinding/cutting means having acentral axis and a plurality of circular blades spaced co-axiallythereon, each blade having a plurality of abrasives circumferentiallyspaced thereon; an engine means configured to drive saidgrinding/cutting means; said grinding/cutting means being displaceablerelative to said vehicle, wherein said grinding/cutting means isconfigured to engage and grind the roadway at a grinding/cutting zoneduring said travel; and a monitoring means including: first displacementsensing means for capturing, during said travel, first distance dataassociated with a distance between a predetermined reference level and alocation on the roadway ahead of the grinding/cutting zone in thedirection of movement; second displacement sensing means for capturing,during said travel, second distance data associated with a distancebetween the predetermined reference level and a location on the roadwaybehind the grinding/cutting zone in the direction of movement; andprocessing means for capturing and using said first and second distancedata to determine depth of cut during grinding/cutting operations.
 26. Amethod for grinding/cutting concrete roadways, the method comprising:(a) operating a ground engaging vehicle configured to travel along aroadway in a direction of movement, the vehicle supporting a headthereon, said head having a central axis and a plurality of circularblades spaced co-axially thereon, each blade having a plurality ofabrasives circumferentially spaced thereon, an engine configured torotationally drive said head about said axis, said head beingdisplaceable relative to said vehicle, wherein said head is configuredto engage and remove material from the roadway at a grinding/cuttingzone during said travel; (b) operating a monitoring system including:one or more first displacement sensors configured to generate, duringsaid travel, first distance data associated with a distance between apredetermined reference level and a location on the roadway ahead of thezone in the direction of movement; one or more second displacementsensors configured to generate, during said travel, second distance dataassociated with a distance between the predetermined reference level anda location on the roadway behind the zone in the direction of movement;a processor configured to capture and use said first and second distancedata to determine depth of cut during grinding/cutting operations; and(c) generating, during said operating (a) and said operating (b), atleast one of the parameters selected from the group consisting ofdistance traveled, area of roadway ground, volume of material removed,abrasive cost per unit area of surface ground, vehicle speed, head rpm,vibration, depth of cut, coolant pressure, coolant inlet temperature,coolant outlet temperature, blade wear, and combinations thereof.